The present invention relates to the field of secure transmission of data packets, and in particular to a new system for automatically encrypting and decrypting data packets between sites on the Internet or other networks of computer networks.
It is becoming increasingly useful for businesses to transmit sensitive information via networks such as the Internet from one site to another, and concomitantly more urgent that such information be secured from uninvited eyes as it traverses the internetwork. At present, unsecured data is replicated at many sites in the process of being transmitted to a destination site, and trade secret or other private information, unless secured, is thereby made available to the public.
It is possible for a user at the sending host to encrypt the data to be sent, and to inform the user who is to receive the data of the encryption mechanism used, along with the key necessary to decrypt. However, this requires communication and coordinated effort on the parts of both the sending and receiving users, and often the users will not take the requisite trouble and the packets will go unencrypted.
Even when these packets are encrypted, the very fact of their being transmitted from user A to user B may be sensitive, and a system is needed that will also make this information private.
FIG. 1 illustrates a network of computer networks, including networks N1, N2 and N3 interconnected via a public network 10 (such as the Internet). When network N1 is designed in conventional fashion, it includes several to many computers (hosts), such as host A and additional hosts 20 and 30. Likewise, network N2 includes host B and additional hosts 40 and 50, while network N3 includes hosts 60-90. There may be many hosts on each network, and many more individual networks than shown here.
When a user at host A wishes to send a file, email or the like to host B, the file is split into packets, each of which typically has a structure such as packet 400 shown in FIG. 7, including data 410 and a header 420. For sending over the Internet, the header 420 will be an internet protocol (IP) header containing the address of the recipient (destination) host B. In conventional fashion, each data packet is routed via the internetwork 10 to the receiving network N2, and ultimately to the receiving host B.
As indicated above, even if the user at host A encrypts the file or data packets before sending, and user B is equipped with the necessary key to decrypt them, the identities of the sending and receiving hosts are easily discernible from the Internet Protocol (IP) addresses in the headers of the packets. Current internetworks do not provide an architecture or method for keeping this information private. More basically, they do not even provide a system for automatic encryption and decryption of data packets sent from one host to another.